Mathematical instrument and the like



J. A. HAGERSTROM.

MATHEMATICAL INSTRUMENT AND THE LIKE.

APPLICATION FILED MAY a1. 1918.

1 ,309, 1 3 1 Patented July 8, 1919.

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JOHN A. HAGELRSTBOM, OF SCRANTON, PENNSYLVANIA, ASSIGNOR TO TECHNICAL SUPPLY COMPANY, OF SORANTON, PENNSYLVANIA, A

JERSEY.

CORPORATION OF N'EW MATHEMATICAL INSTRUMENT AND THE LIKE.

Application filed May 31, 1918.

To all whom it may concern:

Be it known that I, JOHN A. HAGERs'rRoM, a citizen of the United States, and a resident of the city of Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Mathematical Instruments and the like, of which the following is a specification.

The present invention relates to the manufacture of that class of manual implements which are technically called instruments of precision or mathematical instruments, including compasses, dividers, calipers, and other tools specially adapted for measuring, drawing, or delineating various objects, or representations thereof, either for commercial, or scientific, or artistic purposes.

One of the objects of the invention is to produce an instrument of the class mentioned having a practically perfect joint, which can be made easily and expeditiously from plain material, as ordinarily found in stock, and will require but a few simple operations to evolve its component parts and assemble them together.

A further object is the production, in an 7 instrument of the type described, of a secure and smooth-working joint consisting of the minimum number of elements necessary to supply that essential characteristic of a meritorious article of the nature set forth.

A general object is to provide a joint for an instrument of the kind referred to, which shall be of strong and durable construction, not susceptible of derangement through ordinary usage, readily disassembled for inspection or repairs, and economical to manufacture.

Other objects and advantages of the in vention will become apparent as the specification proceeds.

A convenient and satisfactory form of instrument oint, embodying the invention disclosed herein, is illustrated by way of example in the accompanying drawings, wherein:-

Figure I is a side elevation, drawn to an enlarged scale, of the upper part of an instrument in which this improved joint is incorporated;

Fig. II is a central longitudinal section of the same part of the instrument, viewed at right angles to the position shown in the preceding figure;

Specification of Letters Patent.

Patented July 8, 1919.

Serial No. 237,519.

Fig. III is a fragmentary side view showing an appropriate form of material or stock from which the hinge members of the instru-: ment are principally made;

Fig. IV shows the same material in trans verse section, that is, in its original shape;

Fig. V is a side elevation illustrating the shape assumed by the material after the initial operations for producing the joint have been performed thereon;

Fig. VI is an oblique section on the line VIVI of Fig. V, looking at the sectioned part exclusively, in the direction pointed out by the arrows, that is, upwardly to the right;

Fig. VII is a side elevation representing the material, previously operated upon as in Fig. V, now formed with a loop at one end to constitute one of the said hinge members, the loop surrounding a bearing element set therein for the pivot ofthe joint;

Fig. VIII is a cross-section on the line VIII:VIII of Fig. V, looking in either direction; 1

Fig. IX is a section along the oblique line IXIX of Fig. VII, looking downwardly to the right, as pointed out by thearrows in the latter-named figure; i

Fig. X is a detached view, in side elevation, of the bearing element shownwithin the loop in Fig. VII; Fig. XI is an edge view of the same element, again detached;

Fig. XII is an edge view of the complete hinge member represented in side elevation by Fig. VII; and

Fig. XIII is a section showing the material as if severed across the right end of Fig. XII, being ofsame form as appears in Fig. IV, but differently positioned.

As indicated in Fig. I, the instrument to which the improved joint is applied usually has two legs or members A and B. Due to the peculiar formation of the joint, hereinafter described, these members need not be made of broad or heavy material, such as ordinarily is resorted to in order to allow for deep cutting in the process of forming the old type of joint, and subsequently is tooled down and provided with lateral depressions to eliminate surplus material and lighten the instrument to some extent. In carrying out the present invention, it is not required to use any but relatively thin mate-. rial, for instance, light bar metal, and which can be formed by drawing, rolling, or milling'to the desired section. Asimple and useful form as well is shown in the drawing, the same having flat, parallel sides 1 and 2, and rounded or curved edges 3' and-4', best seen in cross-section, Figs. IV and XIII.

fIhe first step in preparing the said members A; and B, to adapt the same as hinge members to be joined together, is to produce at one end of each a reduced or milled-clown portion, denoted bythe reference numerals 8, and 9 in Fig. V. As represented, this reduced portion includes an elongate level surface 8 and curved terminals I and 9. The latter are formed' according to certain radii, hereinafter described. Beyond the terminal, 7 the end of each member is cut to a predetermined angle to produce in addi tionan acutely-beveled portion 10, which is made concave or inwardly rounded, as at 11, F ig. VI, to conform to the curvature of theedge 3, previously mentioned,

Being prepared in the manner above expressed, the said reduced portion of each member A, B, is then turned around over a mandrel, or equivalent contrivance, so that the elongate surface and the terminals thereof, before spoken of, become adjoiningarcs of a circle, as indicated by the reference characters'T, 8 and 9 in Fig. VII, and form together a circular lOOP ClGSigII'HtGCl' as a whole by the reference letter C,

Within each of the loops C is placed a collar or centrally apertured disk 14,; which is brazed therein and designed to afford a bearing in its respective member, A or B, for the hinge pivot, hereinafter described in detail. Preferably, as shown in Figs. II and IX, the said collar, or disk or bear ing, is located flush with the outer face of its member. I p 7 The loop C is next milled or thinned down on one side, as at 12, approximately to onehalf the original thickness of the material composing the members A B, taken flatwise. This thinned-down portion 12 of the loop is bounded inwardly by an overhung ledge 13, formed obliquely across the material in eaclrmember, on the flat side thereof indi cated by the numeral 2.

The collar 14 is. made of less width, measured edgewise, than that of the thinneddown loop C, whereby a recess 15 is left in each loop, with a flat surface 16, encircling the same, so that when two such loops are conjoined facing each other as illustrated, there remains a vacant space therewitliin which precludesany contact of theoppositely-located collars, disks, or bearings, and further confines the necessary frictional adherence of the hinge members solely to the peripheries of their said loops, intermediately of .the contacting surface.

It will be noted that the radius of the 'collar, disk, or bearing 14 illustrated by Fig.

the outside, that is, made flaring outwardly,

as at 18, Fig. IX. These openings and countersinks or concavities become alined through the apposition of the loops pertaining to the members A, B, as shown in Fig. II, and form across them a continuous passage for a pivot to hinge the same one to the other.

Over the hinge. end of the members A B is placed a bifurcated support 19, the,

branches of which terminate in a pair. of annuli 20 and 21, located exteriorly' in rela-. tion to the outer faces of the conjoined loops of. the said members and concentric therewith. The annuli', it will be seen by reference to Fig. II, are similarly concentric with the bearings 14, and their alined openings 17 and concavities A conical protuberance 22 is formed by projecting the inner edge or margin of the annulus 20, and this is received in the concavity of the adjacent bearing 14. The inner edge or margin of the annulus 21, on the other hand,is not deflected, but is threaded to receive a corresponding thread 23, provided around they outer part of a conical head or enlargement 24, of a pivot-screw 25, The tapering portion of the head or enlargement 24fits the concavity in the other bearing 14. The central openings 17 in theopposed bearings enable them to be journaled on a smooth-surfaced intermediate portion of the pivotscrew, while their outwardly-disposed concavities 18 are respectively engaged by the conical protuberance 22 and the similarlyshaped enlargement 24. Thus arranged, the said protuberance and said enlargement. act as centering cones for the hinge members within the branches of the bifurcated sup.

port, and are well adapted to take up the wear of the journaled elements.

External threads are formed aroimd both ends of the pivot-screw 25, one of which, designated by the numeral 26 receives a nut 27, which is permanently secured to it; for instance upsetting or riveting that end of thescrew over the nut, as at 28. Fastened in this manner, the nut serves as a supplementary head to thescrew; and abuts on the underside against the outer face of the annulus 21 at the lower end of the adjoining branch of the support 19, thereby preventity in the bearing 14, thereto appertaining.

This is done when first assembling the parts of the joint, and subsequently to re-adjust the same. Both the nuts 27 and 30 are provided with lateral slots, notches, or recesses, as at 31, to permit the application thereto of a wrench or key when they are screwed over their respective extremities of the pivotscrew.

While a certain preferred embodiment of this instrument joint has been shown and described, it will be understood that changes in the form, arrangements, sizes, proportions and details thereof may be made without departing from the scope of the invention as defined by the appended claims.

Having described my invention what I desire to secure by Letters Patent and claim 1s:

1. An instrument of the nature set forth, comprising hinge members bent circularly upon themselves to form loops, bearing elements seated therein, and a support including means for pivotally sustaining said members from opposite sides of the same.

2. An instrument of the nature set forth, including a pair of hinge members formed with opposite loops adapted for superimposition one upon the other, alined bearing elements seated in said loops, a supportarranged to sustain said members, and pivotal means centering the latter from said elements.

3. An instrument of the nature set forth, comprising duplicate hinge members provided at one end with relatively thin loops adapted to be joined together by inversion, bearing elements seated in said loops, a support having a branch arranged to sustain said members, and pivoting means including abutments centering the latter with regard to said branch from opposite sides of said elements.

4. An instrument of the nature set forth including hinge members formed with loops adapted to be joined together, bearing elements alined in said loops, a bifurcated sup port the branches whereof are arranged to straddle said members, and pivoting means with abutments centering the latter within said branches from opposite sides of said elements.

5. An instrument of the nature set forth comprising hinge members having loops superimposed one upon the other, alined bearing elements seated in said loops, a bifurcated support straddling said members,

one branch of said support being formed with an inwardly projecting protuberance fitted in one of said elements, and a pivot with an enlargement engaging the other one of the bearing elements from the opposite branch of the support.

6. Aninstrument of the nature set forth comprising hinge members with loops facing each other, bearings therein having alined openings with outwardly flaring concavities on opposite sides of said members, a bifurcated support straddling the latter, a proj ection from one branch of said support engaging the concavity in one of said bearings, and a pivot with an enlargement positioned to enter th concavity in the other one of the bearings adjacent to the opposite branch of the support, said pivot passing through said alined concavities and openings.

7. An instrument of the nature set forth comprising superposed hinge members with loops facing each other, oppositely located bearings in said loops, a bifurcated support the branches whereof extend past the outer faces of said bearings, an integral protuberance entering one of the latter from one of said branches, a pivot threaded into the other one of the branches and having an enlargement received in the opposite bearing, and means for holding said pivot exteriorly on the branch of the support carrying said protuberance.

8. An instrument of the nature set forth comprising hinge members having loops contacting laterally one with the other, bearings alined in said loops, a bifurcated sup port straddling the hinge end of said members, one branch of said support having an inwardly extending protuberance arranged to project into one of said bearings, the other branch of the support being provided opposite the other one of the bearings with an internally threaded opening, and a correspondingly threaded element projecting from said opening so as to afford a pivotal 110 connection between both bearings and said branches.

9. An instrument of the nature set forth comprising hinge members having opposed loops formed with contacting surfaces, bear- 115 ings seated in said loops, a bifurcated support the branches whereof terminate in annuli respectively positioned opposite the outer faces of said bearings, one annulus having a reentrant inner edge or margin 120 adapted to engage the bearing on the adjacent side of said support, the other annulus being provided with a threaded opening, and a pivot with an enlargement engaging said opening and thence entering the side of the 125 other bearing thereto adjoining, said pivot operatively suspending said hinge members intermediately of said annuli.

10. An instrument of the nature set forth comprising a pair of hinge members formed 130 with end loops adapted for superimpositiongaged by'a protuberance from the inneredgeormargin of the adjacent annulus, the other annulus having a threaded opening, a pivot with an intermediate enlargement. engaging said opening opposite the bearing: element proximate thereto and" passing at the ends through both of said branches,- a fastening, means for the end of said pivot adjoining said enlargement, and similar means adj 11stably retaining the other end of the pivot.

11 An instrument of the natureset forth, including apair of hinge members having each a reduced portion near one terminal thereof bent circularlyupon itself to -form a 100 the l'ooped' portions of said members oppositely" disposed portions; of reduced Width bent; circularly upon: themselves; to form superimposed: loops, a terminal: of each member adjacent toone end of the reduced portion thereoii being shaped to correspond with the side of themember adjoining the other end of said reduced portion, alined bearing: elements seated; Within said: loops,

.and pivotal means passing through said elementsopenatiively connecting the hinge members together.

JOHN. HAGERSTROM.

C'opiero'f thispatent may'be obta1ned-"orfive:cents each, "by addressing-the Commissioner 01- Patents, Washington, D. 0. 

